🎉 Add downkyicore

[WHMyyds]

🪩 Provide a link to the proposed addition

https://github.com/yaobiao131/downkyicore

😳 Explain why it should be added

基于哔哩下载姬Windows版和AvaloniaUI制作的跨平台版本(支持Windows、linux、macOS)。
开发这个版本目的是由于开发者日常使用macOS，当想下载up视频是偶然间发现了哔哩下载姬Windows版，发现很好用，就是不能支持macOS使用，就基于AvaloniaUI重新开发了一个跨平台版本。

📖 Additional context

No response

🧨 Issue Checklist

• I have checked for other similar issues
• I have explained why this change is important
• I have added necessary documentation (if appropriate)